Division of Applied Life Science (BK21 program), IALS, GyeongSang National University, Jinju 660-701, Republic of Korea.
Food Chem Toxicol. 2013 May;55:144-9. doi: 10.1016/j.fct.2012.12.053. Epub 2013 Jan 10.
Bacterial neuraminidase (NA) is a lynch pin enzyme in the formation of biofilms. Thus NA continues to be one of the key enzymes targeted by bacterial infection. The purpose of this manuscript is to communicate four new naturally derived inhibitors of neuraminidase (IC50s 3.7-24.4μM). All these active species (1-4) contained a resveratrol chemotype, however resveratrol itself was inactive (IC50>100μM). 1-4 were isolated from the 60% aqueous ethanol extract of seeds of Paeonia lactiflora, which exhibited potent neuraminidase inhibition. Purification of the extracts yielded four chiral polyphenols, suffruticosol A (1), suffruticosol B (2), trans-ε-viniferin (3), and trans-gnetin H (4). Mechanistic analysis of 1-4's inhibition showed that they were all reversible, noncompetitive inhibitors. Trans-ε-viniferin (3) underwent trans-cis isomerization, which led to a reduction in inhibition potency. This correlates with the fact that the cis-isomer is a weaker inhibitor of neuraminidase than the trans-isomer. Importantly, significantly different optical rotations ([α]D) compared to previous reports were found for suffruticosols A (+95 vs -34) and B (+136 vs +13). These two species are the most important standard metabolites in the whole paeoniaceae family and therefore correction of this error is important.
细菌神经氨酸酶（NA）是生物膜形成的关键酶。因此，NA 仍然是细菌感染的关键酶之一。本文的目的是交流四种新的天然来源的神经氨酸酶抑制剂（IC50 为 3.7-24.4μM）。所有这些活性物质（1-4）都含有白藜芦醇化学型，但白藜芦醇本身没有活性（IC50>100μM）。1-4 从芍药属植物种子的 60%乙醇提取物中分离得到，该提取物对神经氨酸酶具有很强的抑制作用。提取物的纯化得到了四种手性多酚，分别是 suffruticosol A（1）、suffruticosol B（2）、反式-ε-viniferin（3）和 trans-gnetin H（4）。对 1-4 的抑制机制分析表明，它们都是可逆的、非竞争性抑制剂。反式-ε-viniferin（3）发生顺反异构化，导致抑制活性降低。这与顺式异构体比反式异构体弱的事实相吻合。重要的是，与以前的报告相比，suffruticosols A（+95 比-34）和 B（+136 比+13）的比旋光度（[α]D）有显著差异。这两种物质是整个芍药科最重要的标准代谢物，因此纠正这一错误非常重要。
